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        1 2     

  Subjects -> VETERINARY SCIENCE (Total: 182 journals)
Acta Scientiae Veterinariae     Open Access  
Acta Veterinaria     Open Access  
Acta Veterinaria Brno     Open Access   (Followers: 1)
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 1)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 6)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 7)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 12)
Alexandria Journal of Veterinary Sciences     Open Access  
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 9)
American Journal of Primatology     Hybrid Journal   (Followers: 7)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 16)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 2)
Animal Behaviour     Hybrid Journal   (Followers: 245)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 6)
Animal Health Research Reviews     Hybrid Journal   (Followers: 4)
Animal Reproduction Science     Hybrid Journal   (Followers: 5)
Animals     Open Access   (Followers: 5)
Annales UMCS, Medicina Veterinaria     Open Access  
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Full-text available via subscription   (Followers: 8)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 4)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access   (Followers: 1)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Atatürk Üniversitesi Veteriner Bilimleri Dergisi     Open Access  
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 1)
Australian Veterinary Journal     Hybrid Journal   (Followers: 10)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 4)
Avian Diseases Digest     Full-text available via subscription   (Followers: 3)
Avian Pathology     Hybrid Journal   (Followers: 2)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access  
BMC Veterinary Research     Open Access   (Followers: 5)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 7)
Bulletin of Animal Health and Production in Africa     Full-text available via subscription  
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 7)
Case Reports in Veterinary Medicine     Open Access   (Followers: 4)
Ciência Rural     Open Access   (Followers: 2)
Companion Animal     Full-text available via subscription   (Followers: 4)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 3)
Equine Health     Full-text available via subscription  
Equine Veterinary Education     Hybrid Journal   (Followers: 7)
Equine Veterinary Journal     Hybrid Journal   (Followers: 10)
Ethiopian Veterinary Journal     Open Access   (Followers: 2)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 5)
ILAR Journal     Hybrid Journal  
In Practice     Full-text available via subscription   (Followers: 3)
Indian Journal of Animal Sciences     Open Access   (Followers: 5)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 3)
Intas Polivet     Full-text available via subscription  
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 3)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
InVet     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 2)
ISRN Veterinary Science     Open Access  
Journal of Veterinary Science & Technology     Open Access   (Followers: 3)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 5)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 1)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 4)
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 9)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 2)
Journal of Experimental and Applied Animal Sciences     Open Access   (Followers: 1)
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 4)
Journal of Research in Forestry, Wildlife and Environment     Open Access  
Journal of Small Animal Practice     Hybrid Journal   (Followers: 8)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 22)
Journal of the Hellenic Veterinary Medical Society     Full-text available via subscription   (Followers: 2)
Journal of the South African Veterinary Association     Open Access   (Followers: 1)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 3)
Journal of Veterinary Advances     Open Access   (Followers: 4)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 3)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 4)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 4)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 10)
Journal of Veterinary Internal Medicine     Hybrid Journal   (Followers: 12)
Journal of Veterinary Medical Education     Partially Free   (Followers: 8)
Journal of Veterinary Medicine     Open Access   (Followers: 4)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 2)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 4)
Journal of Veterinary Science & Medical Diagnosis     Full-text available via subscription   (Followers: 1)
Journal of Zoo and Aquarium Research     Open Access   (Followers: 1)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 3)
Kenya Veterinarian     Full-text available via subscription   (Followers: 2)
kleintier konkret     Hybrid Journal  
Kufa Journal For Veterinary Medical Sciences     Open Access  
Livestock     Full-text available via subscription   (Followers: 1)
Macedonian Veterinary Review     Open Access   (Followers: 3)
MEDIA PETERNAKAN - Journal of Animal Science and Technology     Open Access   (Followers: 1)
Medical Mycology     Open Access   (Followers: 3)
Medical Mycology Case Reports     Open Access  

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Journal Cover Veterinary Microbiology
   [10 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0378-1135 - ISSN (Online) 1873-2542
     Published by Elsevier Homepage  [2571 journals]   [SJR: 1.221]   [H-I: 75]
  • Envelope protein complexes of Mycobacterium avium subsp. paratuberculosis
           and their antigenicity
    • Abstract: Publication date: Available online 24 November 2014
      Source:Veterinary Microbiology
      Author(s): Fernando L. Leite , Timothy A. Reinhardt , John P. Bannantine , Judith R. Stabel
      Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne's disease, a chronic enteric disease of ruminant animals. In the present study, blue native PAGE electrophoresis and 2D SDS-PAGE were used to separate MAP envelope protein complexes, followed by mass spectrometry (MS) to identify individual proteins within the complexes. Identity of individual proteins within complexes was further confirmed by MS upon excision of spots from 2D SDS-PAGE gels. Among the seven putative membrane complexes observed, major membrane protein (MAP2121c), a key MAP antigen involved in invasion of epithelial cells, was found to form a complex with cysteine desulfurase (MAP2120c). Other complexes found included those involved in energy metabolism (succinate dehydrogenase complex) as well as a complex formed by Cfp29, a characterized T cell antigen of M. tuberculosis. To determine antigenicity of proteins, Western blot was performed on replicate 2D SDS-PAGE gels with sera from noninfected control cows (n=9) and naturally infected cows in the subclinical (n=10) and clinical (n=13) stages of infection. Clinical animals recognized MAP2121c in greater proportion than subclinical and control cows, whereas cysteine desulfurase recognition was not differentiated by infection status. To further characterize antigenicity, recombinant proteins were expressed for 10 of the proteins identified and evaluated in an interferon-gamma (IFN- γ) release assay as well as immunoblots. This study reveals the presence of protein complexes in the cell envelope of MAP, suggesting protein interactions in the envelope of this pathogen. Furthermore the identification of antigenic proteins with potential as diagnostic targets was characterized.


      PubDate: 2014-11-24T16:11:21Z
       
  • Mycoplasma hyopneumoniae-derived lipid-associated membrane proteins induce
           inflammation and apoptosis in porcine peripheral blood mononuclear cells
           in vitro
    • Abstract: Publication date: Available online 22 November 2014
      Source:Veterinary Microbiology
      Author(s): Fangfang Bai , Bo Ni , Maojun Liu , Zhixin Feng , Qiyan Xiong , Guoqing Shao
      Mycoplasma hyopneumoniae is the causative agent of swine enzootic pneumonia (EP), a disease that causes considerable economic losss in swine industry. Lipid-associated membrane proteins (LAMPs) of mycoplasma play important roles in causing mycoplasma diseases. The present study explores the pathogenic mechanisms of M. hyopneumoniae LAMPs by elucidating their role in modulating the inflammation, apoptosis, and relevant signaling pathways of peripheral blood mononuclear cells (PBMCs) of pig. LAMP treatment inhibited the growth of PBMCs. Up-regulation of cytokines, such as IL-6 and IL-1β, as well as increased production of nitric oxide (NO) and superoxide anion were all detected in the supernatant of LAMPs-treated PBMCs. Furthermore, flow cytometric analysis using dual staining with annexin-V-FITC and propidium iodide (PI) showed that LAMPs of M. hyopneumoniae induced a time-dependent apoptosis in lymphocyts and monocytes from PBMCs, which was blocked by NOS inhibitor or antioxidant. In addition, LAMPs induced the phosphorylation of p38, the ratio of pro-apoptotic Bax protein to anti-apoptotic Bcl-2, activation of caspase-3 and caspase-8, and poly ADP-ribose polymerase (PARP) cleavage in PBMCs. These findings demonstrated that M. hyopneumoniae LAMPs induced the production of proinflammatory cytokines, NO and reactive oxygen species (ROS), and apoptosis of PBMCs in vitro through p38 MAPK and Bax/Bcl-2 signaling pathways, as well as caspase activation.


      PubDate: 2014-11-24T16:11:21Z
       
  • Variants of a genomic island in Aeromonas salmonicida subsp. salmonicida
           link isolates with their geographical origins
    • Abstract: Publication date: Available online 22 November 2014
      Source:Veterinary Microbiology
      Author(s): Jean-Guillaume Emond-Rheault , Antony T. Vincent , Mélanie V. Trudel , Francis Brochu , Brian Boyle , Katherine H. Tanaka , Sabrina A. Attéré , Éric Jubinville , Thomas P. Loch , Andrew D. Winters , Mohamed Faisal , Michel Frenette , Nicolas Derome , Steve J. Charette
      Aeromonas salmonicida subsp. salmonicida is a fish pathogen. Analysis of its genomic characteristics is required to determine the worldwide distribution of the various populations of this bacterium. Genomic alignments between the 01-B526 pathogenic strain and the A449 reference strain have revealed a 51-kb chromosomal insertion in 01-B526. This insertion (AsaGEI1a) has been identified as a new genomic island (GEI) bearing prophage genes. PCR assays were used to detect this GEI in a collection of 139 A. salmonicida subsp. salmonicida isolates. Three forms of this GEI (AsaGEI1a, AsaGEI1b, AsaGEI2a) are now known based on this analysis and the sequencing of the genomes of seven additional isolates. A new prophage (prophage 3) associated with AsaGEI2a was also discovered. Each GEI appeared to be strongly associated with a specific geographic region. AsaGEI1a and AsaGEI2a were exclusively found in North American isolates, except for one European isolate bearing AsaGEI2a. The majority of the isolates bearing AsaGEI1b or no GEI were from Europe. Prophage 3 has also a particular geographic distribution and was found only in North American isolates. We demonstrated that A. salmonicida subsp. salmonicida possesses unsuspected elements of genomic heterogeneity that could be used as indicators to determine the geographic origins of isolates of this bacterium.


      PubDate: 2014-11-24T16:11:21Z
       
  • Complete sequence of a F2:A-:B- plasmid pHN3A11 carrying rmtB and qepA,
           and its dissemination in China
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Xiaojie Chen , Liangying He , Yugu Li , Zhenling Zeng , Yuting Deng , Yahong Liu , Jian-Hua Liu
      Previous studies have confirmed that the spread of rmtB and qepA was mainly mediated by similar F2:A-:B- plasmids. In this study, a representative rmtB and qepA-harbouring F2:A-:B- plasmid, pHN3A11, originating from an Escherichia coli strain of feline origin, was fully sequenced and compared with other IncFII plasmids. pHN3A11 is 76,626bp long with a backbone similar to that of the IncFII plasmids obtained from China (pHK23a, pFOS-HK151325, pXZ) and Canada (pC15-1a). It contains genes encoding addiction (pemI/pemK, hok/mok/sok) and partitioning (parM, parB, and stbB) systems that promote plasmid maintenance during vertical transmission. rmtB, qepA, bla TEM-1, and dfr were found in previously observed contexts, interspersed with different complete or truncated insertion sequences and transposons (ΔIS1, ΔTn2, ΔintI1, ISCR3, 3 IS26, Tn21). Further analyses confirmed that pHN3A11-like plasmids have disseminated in E. coli isolates from pets, food animals and farm environments in China. The successful dissemination of F2:A-:B- type multidrug resistant plasmid among animals may represent a public health risk, and may further worsen the clinical impact.


      PubDate: 2014-11-21T16:05:20Z
       
  • Serological proteome analysis of Corynebacterium pseudotuberculosis
           isolated from different hosts reveals novel candidates for prophylactics
           to control caseous lymphadenitis
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Nubia Seyffert , Renata Faria Silva , Julien Jardin , Wanderson Marques Silva , Thiago Luiz de Paula Castro , Natayme Rocha Tartaglia , Karina Talita de Oliveira Santana , Ricardo Wagner Portela , Artur Silva , Anderson Miyoshi , Yves Le Loir , Vasco Azevedo
      Caseous lymphadenitis (CLA) is a highly prevalent disease in goats and sheep worldwide, which is caused by Corynebacterium pseudotuberculosis. Although several prophylactic methods against CLA have been proposed previously, the identification of new C. pseudotuberculosis proteins that are really produced during the infectious process is still needed to improve efficiency and accuracy in vaccines and diagnostics. In this study, we used optimized conditions for serological proteome analysis (SERPA) in order to identify new immune-reactive proteins in C. pseudotuberculosis culture supernatants of two strains, 1002 and C231, isolated from goats and sheep, respectively. Using a sheep and goat serum pool, 13 novel immune-reactive exoproteins common to the two strains were identified. Four of these proteins present known functions and were already described as immune-reactive proteins in other microorganisms, whereas the other nine are of unknown function and show low similarity with proteins from other bacterial species. These data reveal promising targets for immunoprophylactic methods against CLA.


      PubDate: 2014-11-21T16:05:20Z
       
  • Molecular epidemiology of Mycoplasma hyopneumoniae from outbreaks of
           enzootic pneumonia in domestic pig and the role of wild boar
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Peter Kuhnert , Gudrun Overesch
      Mycoplasma hyopneumoniae is the major cause of enzootic pneumonia (EP) in domestic pigs, a disease with low mortality but high morbidity, having a great economic impact for producers. In Switzerland EP has been successfully eradicated, however, sporadic outbreaks are observed with no obvious source. Besides the possibility of recurrent outbreaks due to persisting M. hyopneumoniae strains within the pig population, there is suspicion that wild boars might introduce M. hyopneumoniae into swine herds. To elucidate possible links between domestic pig and wild boar, epidemiological investigations of recent EP outbreaks were initiated and lung samples of pig and wild boar were tested for the presence of specific genotypes by multilocus sequence typing (MLST). Despite generally different genotypes in wild boar, outbreak strains could be found in geographically linked wild boar lungs after, but so far not before the outbreak. Recurrent outbreaks in a farm were due to the same strain, indicating unsuccessful sanitation rather than reintroduction by wild boar. In another case outbreaks in six different farms were caused by the same strain never found in wild boar, confirming spread between farms due to hypothesized animal transport. Results indicate the presence of identical lineages of wild boar and domestic pig strains, and possible transmission of M. hyopneumoniae between wild boar and pig. However, the role of wild boar might be rather one as a recipient than a transmitter. More important than contact to wild boar for sporadic outbreaks in Switzerland is apparently persistence of M. hyopneumoniae within a farm as well as transmission between farms.


      PubDate: 2014-11-21T16:05:20Z
       
  • New aspects in the biology of Photobacterium damselae subsp. piscicida:
           Pili, motility and adherence to solid surfaces
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Sara Remuzgo-Martínez , María Lázaro-Díez , Daniel Padilla , Belinda Vega , Fátima El Aamri , José Manuel Icardo , Félix Acosta , José Ramos-Vivas
      We describe for the first time the presence of pilus-like structures on the surface of Photobacterium damselae subsp. piscicida (Phdp). The hint to this discovery was the ability of one strain to hemagglutinate human erythrocytes. Further analysis of several Phdp strains ultrastructure by electron microscopy revealed the presence of long, thin fibers, similar to pili of other Gram-negative bacteria. These appendages were also observed and photographed by scanning, transmission electron microscopy and immunofluorescence. Although this fish pathogen has been described as non-motile, all strains tested exhibit twitching motility, a flagella-independent type IV-dependent form of bacterial translocation over surfaces. As far as we are aware, the movement of Phdp bacteria on semi-solid or solid surfaces has not been described previously. Moreover, we speculate that Phdp twitching motility may be involved in biofilm formation. Microscopic examination of Phdp biofilms by microscopy revealed that Phdp biofilm architecture display extensive cellular chaining and also bacterial mortality during biofilm formation in vitro. Based on our results, standardized analyses of Phdp surface appendages, biofilms, motility and their impact on Phdp survival, ecology and pathobiology are now feasible.
      Graphical abstract image

      PubDate: 2014-11-21T16:05:20Z
       
  • Evidence of possible vertical transmission of duck circovirus
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Zhiguo Li , Xin Wang , Ruihua Zhang , Junhao Chen , Linlin Xia , Shaoli Lin , Zhijing Xie , Shijin Jiang
      To test the hypothesis that duck circovirus (DuCV) may be vertically transmitted from infected breeder ducks to their ducklings, we investigated 120 newly hatched ducklings, 30 dead duck embryos and 80 non-embryonated duck eggs with the duplex polymerase chain reaction (PCR). DuCV DNA was present in 15 newly hatched ducklings, 4 duck embryos and 3 non-embryonated eggs. Four ducklings from two flocks were co-infected by DuCV-1 and DuCV-2, three ducklings from three flocks were DuCV-1 single infection, and eight ducklings from six flocks were DuCV-2 single infection. One duck embryo and one non-embryonated egg were positive for both DuCV-1 and DuCV-2 DNAs, one embryo for DuCV-1 DNA, and two embryos and two non-embryonated eggs for DuCV-2 DNA. The findings provide evidence of possible vertical transmission of DuCV and simultaneous transmission of DuCV-1 and DuCV-2 from breeder ducks to ducklings.


      PubDate: 2014-11-21T16:05:20Z
       
  • Phylogenetic analysis of hepatitis E virus in domestic swine and wild boar
           in Germany
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Edmilson F. Oliveira-Filho , Barbara R. Bank-Wolf , Heinz-Jürgen Thiel , Matthias König
      Hepatitis E virus (HEV) is an emerging non-enveloped positive strand RNA virus with worldwide distribution that can cause acute liver disease in humans. The virus has also been detected in both domestic and wild animals. In this study we investigated the presence of HEV in free-living wild boar as well as in domestic swine. A total of 105 domestic swine fecal samples and 124 wild boar sera were tested for the presence of HEV RNA by RT-PCR. A 241 nucleotide (nt) fragment from the capsid gene of HEV from one domestic swine and from 18 wild boars were amplified and sequenced. In addition, the complete capsid of three HEV sequences found in wild boar and the complete genomic sequence of the domestic swine HEV were obtained. Phylogenetic analyses based on both the 241 nt fragments as well as four complete capsid gene sequences demonstrated that all sequences belong to genotype HEV-3.


      PubDate: 2014-11-21T16:05:20Z
       
  • Evaluation of the relationship between Chlamydia pecorum sequence types
           and disease using a species-specific multi-locus sequence typing scheme
           (MLST)
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Martina Jelocnik , Evelyn Walker , Yvonne Pannekoek , Judy Ellem , Peter Timms , Adam Polkinghorne
      Chlamydia pecorum is globally associated with several ovine diseases including keratoconjunctivitis and polyarthritis. The exact relationship between the variety of C. pecorum strains reported and the diseases described in sheep remains unclear, challenging efforts to accurately diagnose and manage infected flocks. In the present study, we applied C. pecorum multi-locus sequence typing (MLST) to C. pecorum positive samples collected from sympatric flocks of Australian sheep presenting with conjunctivitis, conjunctivitis with polyarthritis, or polyarthritis only and with no clinical disease (NCD) in order to elucidate the exact relationships between the infecting strains and the range of diseases. Using Bayesian phylogenetic and cluster analyses on 62 C. pecorum positive ocular, vaginal and rectal swab samples from sheep presenting with a range of diseases and in a comparison to C. pecorum sequence types (STs) from other hosts, one ST (ST 23) was recognised as a globally distributed strain associated with ovine and bovine diseases such as polyarthritis and encephalomyelitis. A second ST (ST 69) presently only described in Australian animals, was detected in association with ovine as well as koala chlamydial infections. The majority of vaginal and rectal C. pecorum STs from animals with NCD and/or anatomical sites with no clinical signs of disease in diseased animals, clustered together in a separate group, by both analyses. Furthermore, 8/13 detected STs were novel. This study provides a platform for strain selection for further research into the pathogenic potential of C. pecorum in animals and highlights targets for potential strain-specific diagnostic test development.


      PubDate: 2014-11-21T16:05:20Z
       
  • Evaluation of hemostaseological status of pigs experimentally infected
           with African swine fever virus
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Hovakim Zakaryan , Elena Karalova , Henrik Voskanyan , Zarine Ter-Pogossyan , Narek Nersisyan , Astghik Hakobyan , David Saroyan , Zaven Karalyan
      African swine fever is a highly contagious hemorrhagic disease of pigs caused by African swine fever virus (ASFV). Hemorrhages are the most frequently reported lesions in acute and subacute forms of ASF. Hemorrhagic lesions are accompanied by impaired hemostasis, which includes thrombocytopenia and changes in the coagulation system. In the present study, experimental infection was conducted to elucidate whether a highly virulent ASFV genotype II circulating in the Trans-Caucasus and Eastern Europe affects the hemostasis of infected pigs. Platelet count changes and platelet size, as well as coagulation parameters were evaluated upon experimental infection. In contrast to other ASFV strains, ASFV genotype II showed a significant decrease in the number of platelets from 3rd dpi onwards. Furthermore, a decrease in platelet size was observed throughout the entire period of experiment. A significant increase in the number of platelet aggregates was observed from the beginning of infection. Unlike other ASFV strains, ASFV genotype II induced a slight shortening of an activated partial thromboplastin time (aPTT) throughout the experiment. Thrombin time (TT) was prolonged from day 5 onwards, whereas no changes in prothrombin time (PT) were found upon infection. The level of d-dimers was permanently higher than in control with a peak on day 3 post-infection. ASFV induced a significant decrease in the level of fibrinogen from day 5 till the end of experiment. Thus, it can be concluded that ASFV genotype II isolated in Armenia affects the hemostasis of infected pigs and causes changes that differ from that of other ASFV strains described previously.


      PubDate: 2014-11-21T16:05:20Z
       
  • E-NTPDase and E-ADA activities in rats experimental infected by
           Cryptococcus neoformans
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Maria Isabel de Azevedo , Laerte Ferreiro , Aleksandro S. Da Silva , Alexandre A. Tonin , Jader B. Ruchel , João F.P. Rezer , Raqueli T. França , Carine E.P. Zimmermann , Daniela B.R. Leal , Marta M.M.F. Duarte , Sonia T.A. Lopes , Mariana M. Flores , Rafael Fighera , Janio M. Santurio
      Cryptococcus neoformans, the etiological agent of cryptococcosis, is an opportunistic fungal pathogen of immunocompromised individuals. The aim of this study was to evaluate the activities of E-NTPDase and E-ADA in rats experimentally infected by C. neoformans var. grubii. Adult rats (35) were divided in two groups: 18 for the control group (uninfected) (A), and 17 for the infected group (B). Each group was separated into three sub-groups (A1, A2, A3—B1, B2, B3), and samples were collected on 10, 20, and 30 days post-infection (PI). Leukocyte counts, IFN-γ, TNF-α, IgM, IgG levels, and E-NTPDase and E-ADA activities were analyzed. It was possible to observe that IgG and IgM seric levels of infected rats were significantly elevated (P <0.01) on days 10, 20 and 30 PI, as well as the levels of TNF-α and INF-γ when compared to uninfected rodents. Regarding E-NTPDase activity in lymphocytes, it was possible to observe that the ATP hydrolysis was significantly decreased on days 20 (P <0.01) and 30 PI (P <0.05), while ADP hydrolysis was significantly reduced only on day 20 PI (P <0.01) when compared with uninfected group. Seric E-ADA activity had a significant reduction (P <0.01) during all three evaluated periods when compared to the control group, while E-ADA activity in lymphocytes increased significantly (P <0.01) when compared to the group A on day 10 PI; however on days 20 and 30 PI, its activity was considerable reduced in lymphocytes of infected animals (P <0.01). Therefore, it is possible to conclude that the infection caused by C. neoformans in immunocompetent rats leads to changes in the purinergic signaling (NTPDase and E-ADA), concomitantly with an inflammatory response (increased levels of cytokines and immunoglobulins) associated with inflammatory infiltrates and histological lesions in the lung.


      PubDate: 2014-11-21T16:05:20Z
       
  • Brucella infection inhibits macrophages apoptosis via Nedd4-dependent
           degradation of calpain2
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Guimei Cui , Pan Wei , Yuxi Zhao , Zhenhong Guan , Li Yang , Wanchun Sun , Shuangxi Wang , Qisheng Peng
      The calcium-dependent protease calpain2 is involved in macrophages apoptosis. Brucella infection-induced up-regulation of intracellular calcium level is an essential factor for the intracellular survival of Brucella within macrophages. Here, we hypothesize that calcium-dependent E3 ubiquitin ligase Nedd4 ubiquitinates calpain2 and inhibits Brucella infection-induced macrophage apoptosis via degradation of calpain2.Our results reveal that Brucella infection induces increases in Nedd4 activity in an intracellular calcium dependent manner. Furthermore, Brucella infection-induced degradation of calpain2 is mediated by Nedd4 ubiquitination of calpain2. Brucella infection-induced calpain2 degradation inhibited macrophages apoptosis. Treatment of Brucella infected macrophages with calcium chelator BAPTA or Nedd4 knock-down decreased Nedd4 activity, prevented calpain2 degradation, and resulted in macrophages apoptosis.


      PubDate: 2014-11-21T16:05:20Z
       
  • Involvement of oxidative stress in subacute toxicity induced by fumonisin
           B1 in broiler chicks
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): A.B. Poersch , F. Trombetta , A.C.M. Braga , S.P. Boeira , M.S. Oliveira , P. Dilkin , C.A. Mallmann , M.R. Fighera , L.F.F. Royes , M.S. Oliveira , A.F. Furian
      Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium spp. It has been reported to be a potential cause of liver cancer in rats and esophageal cancer in humans. The underlying mechanisms of FB1 toxicity are thought to be related to the inhibition of ceramide synthase, causing an accumulation of sphingosine (SO) and sphinganine (SA), which in turn may cause tissue functional impairment and the development of oxidative stress. Therefore, in this study, we investigate the effects of an FB1-contaminated diet on markers of oxidative stress in chick liver. A total of 24 male broiler chicks (Cobb 500) were fed a standard control diet or a diet contaminated with FB1 (100mg/kg) for 21 days, starting on postnatal day one. The feed and animals were weighed on days 0, 7, 14 and 21 to estimate the feed conversion ratio, and at 21 days, the liver weight and liver relative weight were determined. At the end of the experiment, samples of blood and liver were collected. The blood was used to quantify the SA/SO ratio, and the liver was used to determine the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST); ascorbic acid levels (VitC), non-protein thiol (NPSH) levels and TBARS content were also determined. The FB1 diet increased the liver weight, liver relative weight, feed conversion and SA/SO ratio. Furthermore, hepatic TBARS levels, Vit C content and CAT activity were also increased. Conversely, the activities of SOD, GST and NPSH levels, in the liver were not altered by the mycotoxin-contaminated diet. In summary, we showed that subacute exposure of broiler chicks to FB1 induced liver oxidative stress concomitantly with SA/SO accumulation.


      PubDate: 2014-11-21T16:05:20Z
       
  • Diversity of zoonotic enterohepatic Helicobacter species and detection of
           a putative novel gastric Helicobacter species in wild and wild-born
           captive chimpanzees and western lowland gorillas
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Bram Flahou , David Modrý , Kateřina Pomajbíková , Klára J. Petrželková , Annemieke Smet , Richard Ducatelle , Frank Pasmans , Rui M. Sá , Angelique Todd , Chie Hashimoto , Martin Mulama , John Kiang , Mirko Rossi , Freddy Haesebrouck
      A number of Helicobacter species cause gastrointestinal or hepatic disease in humans, including H. pylori, gastric non-H. pylori helicobacters from animal origin and enterohepatic Helicobacter species. Little is known on the presence of Helicobacter species in great apes, our closest living relatives and potential reservoirs of microorganisms that might emerge in humans. The aim of the present study was to investigate the presence of gastric and enterohepatic Helicobacter species in African chimpanzees and gorillas. Fresh fecal samples were collected from wild endangered chimpanzees and critically endangered western lowland gorillas from different African National Parks, as well as wild-born captive animals from primate sanctuaries. Intact Helicobacter bacteria were demonstrated in feces by fluorescence in situ hybridization. Screening using a Helicobacter genus-specific PCR revealed the presence of Helicobacter DNA in the majority of animals in all groups. Cloning and sequencing of 16S rRNA gene fragments revealed a high homology to sequences from various zoonotic enterohepatic Helicobacter species, including H. cinaedi and H. canadensis. A number of gorillas and chimpanzees also tested positive using PCR assays designed to amplify part of the ureAB gene cluster and the hsp60 gene of gastric helicobacters. Phylogenetic analysis revealed the presence of a putative novel zoonotic gastric Helicobacter taxon/species. For this species, we propose the name ‘Candidatus Helicobacter homininae’, pending isolation and further genetic characterization. The presence of several Helicobacter species not only implies a possible health threat for these endangered great apes, but also a possible zoonotic transmission of gastric and enterohepatic helicobacters from these primate reservoirs to humans.


      PubDate: 2014-11-21T16:05:20Z
       
  • Sequence diversity, cytotoxicity and antigenic similarities of the
           leukotoxin of isolates of Mannheimia species from mastitis in domestic
           sheep
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Lida Omaleki , Glenn F. Browning , Stuart R. Barber , Joanne L. Allen , Subramaniam Srikumaran , Philip F. Markham
      Species within the genus Mannheimia are among the most important causes of ovine mastitis. Isolates of these species can express leukotoxin A (LktA), a primary virulence factor of these bacteria. To examine the significance of variation in the LktA, the sequences of the lktA genes in a panel of isolates from cases of ovine mastitis were compared. The cross-neutralising capacities of rat antisera raised against LktA of one Mannheimia glucosida, one haemolytic Mannheimia ruminalis, and two Mannheimia haemolytica isolates were also examined to assess the effect that variation in the lktA gene can have on protective immunity against leukotoxins with differing sequences. The lktA nucleotide distance between the M. haemolytica isolates was greater than between the M. glucosida isolates, with the M. haemolytica isolates divisible into two groups based on their lktA sequences. Comparison of the topology of phylogenetic trees of 16S rDNA and lktA sequences revealed differences in the relationships between some isolates, suggesting horizontal gene transfer. Cross neutralisation data obtained with monospecific anti-LktA rat sera were used to derive antigenic similarity coefficients for LktA from the four Mannheimia species isolates. Similarity coefficients indicated that LktA of the two M. haemolytica isolates were least similar, while LktA from M. glucosida was most similar to those for one of the M. haemolytica isolates and the haemolytic M. ruminalis isolate. The results suggested that vaccination with the M. glucosida leukotoxin would generate the greatest cross-protection against ovine mastitis caused by Mannheimia species with these alleles.


      PubDate: 2014-11-21T16:05:20Z
       
  • Antibody responses of swine following infection with Mycoplasma
           hyopneumoniae, M. hyorhinis, M. hyosynoviae and M. flocculare
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): João Carlos Gomes Neto , Erin L. Strait , Matthew Raymond , Alejandro Ramirez , F. Chris Minion
      Several mycoplasma species possessing a range of virulence have been described in swine. The most commonly described are Mycoplasma hyopneumoniae, Mycoplasma hyorhinis, Mycoplasma hyosynoviae, and Mycoplasma flocculare. They are ubiquitious in many pig producing areas of the world, and except for M. hyopneumoniae, commercial antibody-based assays are lacking for most of these. Antibody cross-reactivity among these four mycoplasma species is not well characterized. Recently, the use of pen-based oral fluids for herd surveillance is of increasing interest. Thus, this study sought to measure pig antibody responses and the level of cross-reactivity in serum and pen-based oral fluids after challenge with four species of swine mycoplasmas. Four groups of four mycoplasma-free growing pigs were separately inoculated with the different mycoplasma species. Pen-based oral fluids and serum samples were collected weekly until necropsy. Species-specific Tween 20 ELISAs were used to measure antibody responses along with four other commercial M. hyopneumoniae ELISAs. Animals from all groups seroconverted to the challenge species of mycoplasma and no evidence of cross-contamination was observed. A delayed antibody response was seen with all but M. hyorhinis-infected pigs. Cross-reactive IgG responses were detected in M. hyopneumoniae- and M. flocculare-infected animals by the M. hyorhinis Tween 20 ELISA, while sera from M. hyosynoviae and M. flocculare-infected pigs were positive in one commercial assay. In pen-based oral fluids, specific anti-M. hyopneumoniae IgA responses were detected earlier after infection than serum IgG responses. In summary, while some antibody-based assays may have the potential for false positives, evidence of this was observed in the current study.


      PubDate: 2014-11-21T16:05:20Z
       
  • Long-term monitoring of 10 selected pathogens in wild boar (Sus scrofa) in
           Sierra Nevada National Park, southern Spain
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Francisco J. Cano-Manuel , Jorge López-Olvera , Paulino Fandos , Ramón C. Soriguer , Jesús M. Pérez , José E. Granados
      Wild boar (Sus scrofa) populations are increasing in the Iberian Peninsula, and population management must include disease management and control. In this study, the epidemiology of 10 selected pathogens (Aujeszky's disease virus – ADV, porcine reproductive and respiratory syndrome virus – PRRSV, porcine influenza virus, porcine circovirus, porcine parvovirus, Erysipelotrix rhusiopathiae, Leptospira pomona, Chlamydia/Chlamydiaceae sp., Salmonella sp. and Mycobacterium bovis) in the wild boar population in Sierra Nevada National Park (SNNP), an open unfenced area, is reported, taking into account wild boar population abundance variation in space and time in an open unfenced environment. A total of 1103 wild boar were sampled in 141 hunting events randomly carried out for sampling in seven hunting seasons (October to February from 2002–2003 to 2009–2010 (except 2007–2008). Prevalence was overall lower than those previously reported for fenced wild boar populations in Spain, but all the pathogens analyzed except PRRSV were considered endemic in the SNNP. ADV, E. rhusiopathiae and total pathogen prevalence were positively correlated to wild boar density. Prevalence in the positive areas was significantly higher in females for ADV, E. rhusiopathiae, L. pomona, Chlamydia/Chlamydiaceae sp. and Salmonella sp., and in males for M. bovis. This longitudinal study provides the first data on the health status of the relatively unmanaged and low density wild boar population of SNNP. It is concluded that non-intensively managed wild boar populations are able to maintain the circulation of several pathogens, even in low prevalences and in open unfenced areas with natural density variation both in time and space.


      PubDate: 2014-11-21T16:05:20Z
       
  • Growth of Mannheimia haemolytica: Inhibitory agents and putative mechanism
           of inhibition
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Abirami Kugadas , Jessica Poindexter , Mee-La Lee , Jegarubee Bavananthasivam , Douglas R. Call , Kelly A. Brayton , Subramaniam Srikumaran
      Leukotoxin-producing Mannheimia haemolytica consistently causes fatal pneumonia in bighorn sheep (BHS) under experimental conditions. Surprisingly, by culture methods, it has been isolated from pneumonic BHS lungs less frequently than other bacteria. However, in one study PCR assays detected M. haemolytica from over 70% of the pneumonic lung samples that were negative for this organism by culture, suggesting that the growth of M. haemolytica is inhibited by other bacteria. Previously, we have shown that Bibersteinia trehalosi inhibits the growth of M. haemolytica. Herein we report that 100% of a diverse panel of B. trehalosi isolates (n =55) tested in a bacterial competition assay inhibited the growth of M. haemolytica, suggesting that the inhibitory phenotype is conserved. Further, no plasmids were isolated from any of the 30 B. trehalosi isolates tested, suggesting that the effectors are chromosomally encoded. An earlier study by us showed that Pasteurella multocida also inhibits the growth of M. haemolytica. However, M. haemolytica has not been isolated even from pneumonic BHS lungs that did not carry B. trehalosi or P. multocida. Consequently, we tested Staphylococcus spp., Streptococcus spp., and Escherichia coli, the bacteria that have been detected frequently in pneumonic BHS lungs, for possible inhibition of M. haemolytica. Neither the Staphylococcus spp. nor the Streptococcus sp. strains inhibited the growth of M. haemolytica. E. coli inhibited the growth of M. haemolytica by a proximity-dependent mechanism. Growth inhibition of M. haemolytica by several bacterial species is likely to contribute to the infrequent detection of this bacterium from pneumonic BHS lungs by culture.


      PubDate: 2014-11-21T16:05:20Z
       
  • Lung pathogenicity of European genotype 3 strain porcine reproductive and
           
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Eefke Weesendorp , Johanna M.J. Rebel , Ditta J. Popma-De Graaf , Helmi P.D. Fijten , Norbert Stockhofe-Zurwieden
      Porcine reproductive and respiratory syndrome (PRRS) is difficult to control due to a high mutation rate of the PRRS virus (PRRSV) and the emergence of virulent strains. The objective of this study was to analyse early and late pathological responses in the respiratory tract after infection with the European PRRSV subtype 3 strain Lena in comparison to two European PRRSV subtype 1 strains: Belgium A and Lelystad-Ter Huurne (LV). For each virus strain, groups of twelve pigs were inoculated, and four pigs per group were euthanized at days 3, 7 and 35 post-infection (p.i.) for consecutive examination. Infection with strain Lena resulted in a more severe disease than with the subtype 1 strains, an inflammatory response within the first week of infection with expression of IL-1α in the lung and lymph node, and an influx of neutrophils and monocytes in bronchoalveolar lavage fluid (BALF). Infection with strain Belgium A or LV resulted in mild or no pathology within the first week of infection, but inflammatory cell influx in the lung interstititium was increased at the end of the experiment at day 35 p.i. At five weeks p.i., all strains induced a higher percentage of cytotoxic T cells and higher levels of IFN-γ producing cells in BALF. This might have contributed to clearance of virus. In general, subtype 3 strain Lena induced a stronger early inflammatory response which led to more severe clinical disease and pathology. On the other hand, this may have supported an enhanced or faster clearance of virus in tissues, compared to subtype 1 strains.


      PubDate: 2014-11-21T16:05:20Z
       
  • Vaccination with recombinant 4×M2e.HSP70c fusion protein as a
           universal vaccine candidate enhances both humoral and cell-mediated immune
           responses and decreases viral shedding against experimental challenge of
           H9N2 influenza in chickens
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Mehran Dabaghian , Ali Mohammad Latify , Majid Tebianian , Hassan Nili , Ali Reza Tevangar Ranjbar , Ali Mirjalili , Mashallah Mohammadi , Reza Banihashemi , Seyyed Mahmoud Ebrahimi
      As cellular immunity is essential for virus clearance, it is commonly accepted that no adequate cellular immunity is achieved by all available inactivated HA-based influenza vaccines. Thus, an improved influenza vaccine to induce both humoral and cell-mediated immune responses is urgently required to control LPAI H9N2 outbreaks in poultry farms. M2e-based vaccines have been suggested and developed as a new generation of universal vaccine candidate against influenza A infection. Our previous study have shown that a prime-boost administration of recombinant 4×M2e.HSP70c (r4M2e/H70c) fusion protein compared to conventional HA-based influenza vaccines provided full protection against lethal dose of influenza A viruses in mice. In the present study, the immunogenicity and protective efficacy of (r4M2e/H70c) was examined in chickens. The data reported herein show that protection against H9N2 viral challenge was significantly increased in chickens by injection of r4M2e/H70c compared with injection of conventional HA-based influenza vaccine adjuvanted with MF59 or recombinant 4×M2e (r4M2e) without HSP70c. Oropharyngeal and cloacal shedding of the virus was detected in all of the r4M2e/H70c vaccinated birds at 2 days after challenge, but the titer was low and decreased rapidly to reach undetectable levels at 7 days after challenge. Moreover, comparison of protective efficacy against LPAI H9N2 in birds intramuscularly immunized with r4M2e/H70c likely represented the ability of the M2e-based vaccine in providing cross-protection against heterosubtypic H9N2 challenge and also allowed the host immune system to induce HA-homosubtype neutralizing antibody against H9N2 challenge. This protective immunity might be attributed to enhanced cell-mediated immunity, which is interpreted as increased lymphocytes proliferation, increased levels of Th1-type (IFN-γ) and Th2-type (IL-4) cytokines production and increased CD4+ to CD8+ ratios, resulting from the injection of four tandem repeats of the ectodomain of the conserved influenza matrix protein M2 (4×M2e) genetically fused to C-terminus of Mycobacterium tuberculosis HSP70 (mHSP70c).


      PubDate: 2014-11-21T16:05:20Z
       
  • A novel parainfluenza virus type 3 (PIV3) identified from goat herds with
           respiratory diseases in eastern China
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Wenliang Li , Li Mao , Suping Cheng , Qiusheng Wang , Jiachun Huang , Jiawu Deng , Zhongyu Wang , Wenwen Zhang , Leilei Yang , Fei Hao , Yonglong Ding , Yinhua Sun , Jianzhong Wei , Ping Jiang , Jieyuan Jiang
      Parainfluenza virus type 3 (PIV3) is one of the most important viral respiratory pathogens for humans and for many animals, but goat infection has been rarely reported. Starting in Aug 2013, goats in the Jiangsu and Anhui provinces of eastern China suffered severe respiratory diseases. In order to identify the causative agent, numerous related pathogens were tested with RT-PCR or PCR. A unique PIV3 strain was detected in most of the clinical nasal swabs or serum samples. The virus was isolated on MDBK cells and characterized by RT-PCR, nucleotide sequence analysis and hemagglutination test. The entire M and F gene coding regions, HN, 5′-UTR-N and L gene fragments were amplified using pairs of degenerate primers. Nucleotide, amino acid sequence alignments and phylogenetic analyses based on these genes indicated that the goat-derived PIV3 strain was distinct from previously reported BPIV3 genotypes and HPIV3 strains. The novel isolate, named JS2013, might be a potentially new member of the respirovirus genus. Goats were experimentally infected with JS2013 culture. The virus-inoculated goats displayed coughing and nasal discharges that were related to respiratory diseases. Viremia and virus shedding were detected during 4–10 days post-inoculation (dpi). Virus-specific HI antibodies became positive from 14dpi. This is the first report of the detection of PIV3 from Chinese goat herds and genetic and pathogenetic characterization of the novel goat-derived PIV3.


      PubDate: 2014-11-21T16:05:20Z
       
  • Pathogenicity and genomic characterization of a pseudorabies virus variant
           isolated from Bartha-K61-vaccinated swine population in China
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Yuzi Luo , Na Li , Xin Cong , Chun-Hua Wang , Min Du , Lin Li , Bibo Zhao , Jin Yuan , Dan-Dan Liu , Su Li , Yongfeng Li , Yuan Sun , Hua-Ji Qiu
      Pseudorabies (PR) or Aujeszky's disease (AD), caused by pseudorabies virus (PRV), is an economically important viral disease worldwide. Recently, PR outbreaks occurred in a large number of Bartha-K61-vaccinated swine herds in many regions of China. Here, we isolated a PRV variant, named TJ strain, from a Bartha-K61-vaccinated pig farm in China, evaluated the pathogenicity of the TJ strain in susceptible animals and analyzed its complete genomic sequence obtained by 454 pyrosequencing. Vaccination-challenge experiment in sheep showed that the classical Bartha-K61 vaccine could not provide complete protection against the challenge with the PRV TJ strain. In mice, the 50% lethal dose (LD50) of the TJ strain (102.3 TCID50) was lower than that of the classical PRV SC strain (103.0 TCID50). Furthermore, the TJ strain displayed higher mortality for pigs, as compared with the SC strain. The PRV TJ strain genome was determined to be 143,642bp in length, encoding 67 open reading frames. The TJ strain was clustered to an independent branch together with some recent PRV isolates in China in the phylogenetic tree, which was relatively distant from previous PRV isolates. The TJ strain showed unique variations in the viral proteins that play key roles in the viral replication cycle. Taken together, the TJ strain is a highly pathogenic PRV variant with unique molecular signatures. Further studies are needed to explore the relevance of the sequence differences to the virulence alteration of the PRV variant.


      PubDate: 2014-11-21T16:05:20Z
       
  • The spray-drying process is sufficient to inactivate infectious porcine
           epidemic diarrhea virus in plasma
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Priscilla F. Gerber , Chao-Ting Xiao , Qi Chen , Jianqiang Zhang , Patrick G. Halbur , Tanja Opriessnig
      Porcine epidemic diarrhea virus (PEDV) is considered an emergent pathogen associated with high economic losses in many pig rearing areas. Recently it has been suggested that PEDV could be transmitted to naïve pig populations through inclusion of spray-dried porcine plasma (SDPP) into the nursery diet which led to a ban of SDPP in several areas in North America and Europe. To determine the effect of spray-drying on PEDV infectivity, 3-week-old pigs were intragastrically inoculated with (1) raw porcine plasma spiked with PEDV (RAW-PEDV-CONTROL), (2) porcine plasma spiked with PEDV and then spray dried (SD-PEDV-CONTROL), (3) raw plasma from PEDV infected pigs (RAW-SICK), (4) spray-dried plasma from PEDV infected pigs (SD-SICK), or (5) spray-dried plasma from PEDV negative pigs (SD-NEG-CONTROL). For the spray-drying process, a tabletop spray-dryer with industry-like settings for inlet and outlet temperatures was used. In the RAW-PEDV-CONTROL group, PEDV RNA was present in feces at day post infection (dpi) 3 and the pigs seroconverted by dpi 14. In contrast, PEDV RNA in feces was not detected in any of the pigs in the other groups including the SD-PEDV-CONTROL group and none of the pigs had seroconverted by termination of the project at dpi 28. This work provides direct evidence that the experimental spray-drying process used in this study was effective in inactivating infectious PEDV in the plasma. Additionally, plasma collected from PEDV infected pigs at peak disease did not contain infectious PEDV. These findings suggest that the risk for PEDV transmission through commercially produced SDPP is minimal.


      PubDate: 2014-11-21T16:05:20Z
       
  • Wild ungulates as sentinel of BTV-8 infection in piedmont areas
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): E. Grego , M. Sossella , D. Bisanzio , M.C. Stella , G. Giordana , L. Pignata , L. Tomassone
      Bluetongue caused by the genotype 8 virus (BTV-8) appeared for the first time in BTV free areas in northern Italy in 2008. The presence of domestic animals outbreaks, abundant wild ungulates populations, and ongoing regional BTV control plans, made this area interesting to evaluate the role of wild ruminants in BTV-8 epidemiology. We analyzed spleen samples from hunted red deer (Cervus elaphus), roe deer (Capreolus capreolus) and Alpine chamois (Rupicapra rupicapra) by quantitative RT-PCR. Samples were collected from 2008 to 2011 in two provinces of Piedmont region. BTV-8 was detected in all ungulate species, confirming their receptivity to the infection. However, the viral load in the positive specimens was low, and decreased from 2008 to 2011. These results, together with the extinction of the epidemic following a regional livestock vaccination campaign, lead to hypothesize that wild ungulates were an epiphenomenon and they had not an important role in the domestic transmission cycle of BTV-8 in this area. In spite of this, wild ruminants appear to be good sentinels of BTV circulation and their monitoring could be useful for surveillance in piedmont areas.


      PubDate: 2014-11-21T16:05:20Z
       
  • Identification of bluetongue virus and epizootic hemorrhagic disease virus
           serotypes in French Guiana in 2011 and 2012
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Cyril Viarouge , Renaud Lancelot , Germain Rives , Emmanuel Bréard , Manuelle Miller , Xavier Baudrimont , Virginie Doceul , Damien Vitour , Stéphan Zientara , Corinne Sailleau
      In French Guiana, the sero- and viro-prevalence of Bluetongue virus (BTV) is high but the circulating serotypes remain unknown. No data are available regarding the prevalence of Epizootic hemorrhagic disease (EHD). This study was conducted to assess the prevalence and to identify the circulating serotypes of these two Orbiviruses in this region (BTV and EHDV). Blood samples were collected in main livestock areas, from 122 young cattle between June and August 2011, to perform virological (PCR and viral isolation) and serological (ELISA) analyses. Moreover, samples from sheep and goat showing BTV-like clinical signs and from newly imported animals were analyzed using the same assays. Results confirmed an important viral circulation, with viro- and seroprevalence of 85% and 84% and 60% and 40% for BTV and EHDV, respectively. Ten Orbivirus serotypes were identified (BTV-1, 2, 6, 10, 12, 13, 17 and 24, EHDV-1 and 6). The circulation of many serotypes in intertropical America and in the Caribbean region underlines the need to establish measures to monitor and control animal movements.


      PubDate: 2014-11-21T16:05:20Z
       
  • Canine distemper outbreak in raccoons suggests pathogen interspecies
           transmission amongst alien and native carnivores in urban areas from
           Germany
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Zaida Rentería-Solís , Christine Förster , Angelika Aue , Ulrich Wittstatt , Gudrun Wibbelt , Matthias König
      From December 2012 to May 2013, an outbreak occurred among urban wild carnivores from Berlin. We collected 97 free-ranging raccoons from the city area. PCR assays, histopathology and immunohistochemistry confirmed canine distemper virus (CDV) infection in 74 raccoons. Phylogenetic analysis of haemagglutinin gene fragments (1767 nucleotides) of CDV isolated from four raccoons showed close relation to CDV isolates from foxes from Germany and a domestic dog from Hungary; all belonging to the “Europe” lineage of CDV. These study results suggest an inter-species transmission of CDV as the origin for the outbreak among the raccoon population. Implications for domestic pets and suggested interspecies transmission between urban wildlife and raccoons are discussed. This is the first major outbreak of CDV amongst free-ranging raccoons in Europe.


      PubDate: 2014-11-21T16:05:20Z
       
  • Pathogenesis of porcine epidemic diarrhea virus isolate
           (US/Iowa/18984/2013) in 3-week-old weaned pigs
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): D.M. Madson , D.R. Magstadt , P.H.E. Arruda , H. Hoang , D. Sun , L.P. Bower , M. Bhandari , E.R. Burrough , P.C. Gauger , A.E. Pillatzki , G.W. Stevenson , B.L. Wilberts , J. Brodie , K.M. Harmon , C. Wang , R.G. Main , J. Zhang , K.J. Yoon
      Porcine epidemic diarrhea virus (PEDV) is associated with clinical diarrhea in naïve swine of all ages. This report describes timing of antibody generation and disease progression following infection with a US PEDV isolate by assessing fecal viral shedding, morphometric analysis of intestinal lesions, and magnitude of immunohistochemical staining. Sixty-three, 3-week-old pigs were randomly allocated into control (n =27) and challenged (n =36) groups. Challenged pigs were administered 1mL of 1×103 PFU/mL of US/Iowa/18984/2013 PEDV isolate by oro-gastric gavage. Three control and four challenged pigs were necropsied on days post-inoculation (dpi) 1, 2, 3, 4, 7, and weekly thereafter, until study termination on dpi 35. Clinical disease, fecal shedding, body weight, and temperature were monitored during the study period. Diarrhea was observed in challenged pigs beginning for some on dpi 2, affecting a majority of pigs by dpi 6 and subsiding by dpi 10. Average daily gain was significantly lower (P <0.001) for one week post-infection in challenged pigs. PEDV was detected in feces by PCR on dpi 1 and continued in a subset of pigs until dpi 24. PEDV-specific antigen was detected in villous enterocytes of challenged pigs by immunohistochemistry (IHC) on dpi 1, 2, 3, 4, 7, and 14. Microscopic lesions included severe diffuse atrophic enteritis with significantly reduced (P <0.001) villous length observed on dpi 3, 4, and 7. Under the conditions of this study, fecal shedding of PEDV and IHC staining can precede and continue beyond the observation of clinical signs, thus increasing the risk of viral transmission.


      PubDate: 2014-11-21T16:05:20Z
       
  • Efficacy of CSF vaccine CP7_E2alf in piglets with maternally derived
           antibodies
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): P.L. Eblé , S. Quak , Y. Geurts , H.W.M. Moonen-Leusen , W.L.A. Loeffen
      There is a need for live DIVA (differentiating infected from vaccinated animals) vaccines against classical swine fever (CSF). The aim of this study was to investigate whether vaccination with the chimeric pestivirus vaccine CP7_E2alf is efficacious to protect young piglets born from vaccinated sows, thus with maternally derived antibodies (MDAs). Groups of 10 piglets each, with or without MDAs, were vaccinated either intramuscularly (IM), at an age of 3 or 6 weeks, or orally (OR), at an age of 6 weeks. Five piglets of each group were challenged with CSFV strain Koslov and protection against clinical disease, virus shedding and transmission were studied. Vaccination with CP7_E2alf, both in the presence of MDA's and in piglets without MDA's, protected against severe clinical signs, but virus shedding from most inoculated piglets and transmission to contact pigs was observed. However, virus transmission in the vaccinated piglets was significantly reduced as compared to non-vaccinated piglets, although the reproduction ratio's R calculated from the results in the vaccinated pigs from our study were not yet significantly below 1. The efficacy of vaccination with CP7_E2alf in the presence of MDAs (R IMvac =0.8, R ORvac =0.4) seemed to be slightly less as compared to vaccination in the absence of MDAs (R IMvac =0.2, R ORvac =0). On a population level, the results suggest that the CP7_E2alf vaccine is an effective tool in the control and eradication of CSF and, moreover, can be applied for both IM and oral use for young age groups, with MDAs having a limited effect on the efficacy.


      PubDate: 2014-11-21T16:05:20Z
       
  • Molecular characterisation of lineage IV peste des petits ruminants virus
           using multi gene sequence data
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): K. Senthil Kumar , Aravindh Babu , G. Sundarapandian , Parimal Roy , A. Thangavelu , K. Siva Kumar , R. Arumugam , N.D.J. Chandran , Murali Muniraju , Mana Mahapatra , Ashley C. Banyard , B. Murali Manohar , Satya Parida
      Peste des petits ruminants is responsible for an economically important plague of small ruminants that is endemic across much of the developing world. Here we describe the detection and characterisation of a PPR virus from a recent outbreak in Tamil Nadu, India. We demonstrate the isolation of PPR virus from rectal swab and highlight the potential spread of disease to in-contact animals through faecal materials and use of faecal material as non-invasive method of sampling for susceptible wild ruminants. Finally we have performed a comprehensive ‘multi-gene’ assessment of lineage IV isolates of PPRV utilising sequence data from our study and publically available partial N, partial F and partial H gene data. We describe the effects of grouping PPRV isolates utilising different gene loci and conclude that the variable part of N gene at C terminus gives the best phylogenetic assessment of PPRV isolates with isolates generally clustering according to geographical isolation. This assessment highlights the importance of careful gene targeting with RT-PCR to enable thorough phylogenetic analysis.


      PubDate: 2014-11-21T16:05:20Z
       
  • Temporal insight into the natural generation of a new reassortant porcine
           influenza virus in a swine holding
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Chiara Chiapponi , Laura Baioni , Andrea Luppi , Ana Moreno , Alberto Castellan , Emanuela Foni
      The influenza A virus (IAV) subtypes H1N1, H3N2 and H1N2 are the most prevalent subtypes in swine in Italy. Reassortant influenza A viruses subtypes in swine appeared in European pig population. In particular reassortant viruses carrying genome segment from the pandemic H1N1 (H1N1pdm) are reported in many European countries, including Italy. In a 1000 sows farrow-to feeder farm, in Northern Italy, we isolated 10 IAVs from recurrent episodes of respiratory disease in 45–70 days-old pigs from September 2012 to June 2013. The antigenic and genetic characterization of the swine IAV isolates showed the contemporary circulation of H1N1 avian-like and H1N1pdm strains in the first outbreak. The analysis of the viruses isolated subsequently showed the circulation of H1N1pdm IAV and then the establishment of a new previously undescribed H1N1 reassortant strain with a pandemic derived hemagglutinin gene and all the other seven segments of swine H1N1 avian-like lineage.


      PubDate: 2014-11-21T16:05:20Z
       
  • Molecular identification of erythrocytic necrosis virus (ENV) from the
           blood of Pacific herring (Clupea pallasii)
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Eveline J. Emmenegger , Jolene A. Glenn , James R. Winton , William N. Batts , Jacob L. Gregg , Paul K. Hershberger
      Viral erythrocytic necrosis (VEN) is a condition affecting the red blood cells of more than 20 species of marine and anadromous fishes in the North Atlantic and North Pacific Oceans. Among populations of Pacific herring (Clupea pallasii) on the west coast of North America the disease causes anemia and elevated mortality in periodic epizootics. Presently, VEN is diagnosed by observation of typical cytoplasmic inclusion bodies in stained blood smears from infected fish. The causative agent, erythrocytic necrosis virus (ENV), is unculturable and a presumed iridovirus by electron microscopy. In vivo amplification of the virus in pathogen-free laboratory stocks of Pacific herring with subsequent virus concentration, purification, DNA extraction, and high-throughput sequencing were used to obtain genomic ENV sequences. Fragments with the highest sequence identity to the family Iridoviridae were used to design four sets of ENV-specific polymerase chain reaction (PCR) primers. Testing of blood and tissue samples from experimentally and wild infected Pacific herring as well as DNA extracted from other amphibian and piscine iridoviruses verified the assays were specific to ENV with a limit of detection of 0.0003ng. Preliminary phylogenetic analyses of a 1448bp fragment of the putative DNA polymerase gene supported inclusion of ENV in a proposed sixth genus of the family Iridoviridae that contains other erythrocytic viruses from ectothermic hosts. This study provides the first molecular evidence of ENV's inclusion within the Iridoviridae family and offers conventional PCR assays as a means of rapidly surveying the ENV-status of wild and propagated Pacific herring stocks.


      PubDate: 2014-11-21T16:05:20Z
       
  • Effect of booster shot and investigation of vaccination efficacy period
           against herpesviral haematopoietic necrosis (HVHN) in goldfish Carassius
           auratus
    • Abstract: Publication date: Available online 15 November 2014
      Source:Veterinary Microbiology
      Author(s): Takafumi Ito , Yukio Maeno
      In this study, the efficacy period of an intraperitoneal vaccination and effect of a booster shot of vaccine against herpesviral haematopoietic necrosis (HVHN) in goldfish Carassius auratus were investigated. Cell culture supernatant of cyprinid herpesvirus 2 (CyHV-2), causative agent of HVHN, propagated in goldfish fin (GFF) cells was inactivated with formalin (0.1% v/v) for 2 days at 4°C. Three groups of the variety Ryukin were individually intraperitoneally injected with the vaccine and each group was separately maintained in replicate tanks. After 4 weeks (Vaccinated-4w-1 and 2) and 8 weeks (Vaccinated-8w-1 and 2) from the first vaccination, the fish were CyHV-2-challenged by the immersion route (10 TCID50 l−1). In addition, the other vaccinated group of fish were injected with a booster vaccine 4 weeks after the first vaccination as the Vaccinated-booster groups, then the fish of these groups were CyHV-2-challenged by the immersion route (10 TCID50 l−1) after 8 weeks from the first vaccination. The mean of the relative percentage survival (RPS) values of the Vaccinated- 4w and 8w groups showed 42.5 and 57.6%, respectively. In addition, the mean RPS value of Vaccinated-booster groups showed 63.6%. Statistical analysis showed significantly higher survival rates in all the vaccinated groups than those of the respective negative control groups using Fisher's exact test. Moreover, the survival rates of vaccinated–booster groups were significantly higher (p =0.036) compared with the respective control groups by Student's T test. The present study shows the efficacy period of the vaccine is at least 8 weeks and a booster shot showed a tendency to enhance the protection against HVHN in goldfish.


      PubDate: 2014-11-21T16:05:20Z
       
  • A20 promotes Brucella intracellular growth via inhibition of macrophage
           cell death and activation
    • Abstract: Publication date: Available online 18 November 2014
      Source:Veterinary Microbiology
      Author(s): Pan Wei , Guimei Cui , Qiang Lu , Li Yang , Zhenhong Guan , Wanchun Sun , Yuxi Zhao , Shuangxi Wang , Qisheng Peng
      The zinc-finger protein A20 has crucial physiological functions as a dual inhibitor of macrophage activation and apoptosis in tumor necrosis factor receptor1 (TNFR1) signaling pathway. Brucella infection can induce A20 expression in macrophages. Here, we hypothesize that A20 promotes Brucella intracellular growth via inhibition of activation and apoptosis of macrophages. To test this hypothesis, we stably incorporated mouse A20-shRNA into the RAW264.7 cells by lentiviral gene transfer to successfully knockdown A20. A20-deficient RAW264.7 cells were subsequently challenged with Brucella abortus and colony formation Units (CFUs) of bacteria, TNFα production, NF-kB activation, macrophages apoptosis and cell death were evaluated. The A20 knockdown was shown to effectively promote B.abortus-stimulated TNFα release, NF-kB activation and macrophage cell death, which suppressed B.abortus intracellular replication. Unexpectedly, deficiency of A20 failed to lead to B.abortus-induced macrophage apoptosis. A20 deficiency coupled NF-kB inhibition promoted caspase-8 dependent B.abortus-induced macrophage apoptosis. These findings provide a novel mechanism by which Brucella intracellular growth within macrophages occurs through up-regulation of A20 thereby limiting activation and macrophages cell death.


      PubDate: 2014-11-21T16:05:20Z
       
  • Vaccination with a genotype 1 modified live vaccine against porcine
           reproductive and respiratory syndrome virus significantly reduces viremia,
           viral shedding and transmission of the virus in a quasi-natural
           experimental model
    • Abstract: Publication date: Available online 15 November 2014
      Source:Veterinary Microbiology
      Author(s): Emanuela Pileri , Elisa Gibert , Ferran Soldevila , Ariadna García-Saenz , Joan Pujols , Ivan Diaz , Laila Darwich , Jordi Casal , Marga Martín , Enric Mateu
      The present study assessed the efficacy of vaccination against genotype 1 porcine reproductive and respiratory syndrome virus (PRRSV) in terms of reduction of the transmission. Ninety-eight 3-week-old piglets were divided in two groups: V (n=40) and NV (n=58) that were housed separately. V animals were vaccinated with a commercial genotype 1 PRRSV vaccine while NV were kept as controls. On day 35 post-vaccination, 14 NV pigs were separated and inoculated intranasally with 2ml of a heterologous genotype 1 PRRSV isolate (“seeder” pigs, SP). The other V and NV animals were distributed in groups of 5 pigs each. Two days later, one SP was introduced into each pen to expose V and NV to PRRSV. Sentinel pigs were allocated in adjacent pens. Follow-up was of 21 days. All NV (30/30) became viremic after contact with SP while only 53% of V pigs were detected so (21/40, p<0.05). Vaccination shortened viremia (12.2±4 versus 3.7±3.4 days in NV and V pigs, respectively, p<0.01). The 50% survival time for becoming infected (Kaplan-Meier) for V was 21 days (CI95% =14.1-27.9) compared to 7 days (CI95% =5.2-8.7) for NV animals (p<0.01). These differences were reflected in the R value as well: 2.78 (CI95% =2.13-3.43) for NV and 0.53 (CI95% =0.19-0.76) for V pigs, (p<0.05). All sentinel pigs (10/10) in pens adjacent to NV+SP pens got infected compared to 1/4 sentinel pigs allocated contiguous to a V+SP pen. These data show that vaccination of piglets significantly decrease parameters related to PRRSV transmission.


      PubDate: 2014-11-21T16:05:20Z
       
  • IFC - Aims &amp; Scope, EDB, Publication Information
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2




      PubDate: 2014-11-21T16:05:20Z
       
  • Novel canine bocavirus strain associated with severe enteritis in a dog
           litter
    • Abstract: Publication date: 7 November 2014
      Source:Veterinary Microbiology, Volume 174, Issues 1–2
      Author(s): Rogier Bodewes , Stefanie Lapp , Kerstin Hahn , André Habierski , Christine Förster , Matthias König , Peter Wohlsein , Albert D.M.E. Osterhaus , Wolfgang Baumgärtner
      Bocaviruses are small non-enveloped viruses with a linear ssDNA genome, that belong to the genus Bocaparvovirus of the subfamiliy Parvovirinae. Bocavirus infections are associated with a wide spectrum of disease in humans and various mammalian species. Here we describe a fatal enteritis associated with infection with a novel strain of canine bocavirus 2 (CaBoV-2), that occurred in a litter of German wirehaired pointers. Necropsy performed on three puppies revealed an enteritis reminiscent of canine parvovirus associated enteritis, accompanied with signs of lymphocytolytic disease in bone marrow, spleen, lymph nodes and thymus. While other major causes of enteritis of young dogs, including canine parvovirus, were excluded, by random PCR in combination with next-generation sequencing, a novel CaBoV-2 strain was detected. Phylogenetic analysis of the genome of this novel canine bocavirus strain indicated that this virus was indeed most closely related to group 2 canine bocaviruses. Infection with canine bocavirus was confirmed by in situ hybridization, which revealed the presence of CaBoV-2 nucleic acid in the intestinal tract and lymphoid tissues of the dogs. In a small-scale retrospective analysis concerning the role of CaBoV-2 no additional cases were identified. The findings of this study provide novel insights into the pathogenicity of canine bocaviruses.


      PubDate: 2014-11-21T16:05:20Z
       
  • Serological Relationships among Subgroups in Bovine Viral Diarrhoea Virus
           Genotype 1 (BVDV-1)
    • Abstract: Publication date: Available online 8 November 2014
      Source:Veterinary Microbiology
      Author(s): Gizem Alpay , Kadir Yeşilbağ
      Bovine viral diarrhoea virus (BVDV) has various economic impacts associated with diarrhoea, poor performance, an increase in the frequency of other infections and lethal outcomes. Both genotypes, namely BVDV-1 and BVDV-2, as well as different subgroups within these genotypes have been reported world wide. Understanding the serological differences among the BVDV subgroups is important for disease epidemiology and prevention as well as vaccination programs. The aim of this study was to determine the serological relatedness among the subgroups in BVDV-1. For that purpose, sheep hyperimmune sera were collected against representative strains from 6 of the subgroups of BVDV-1 (BVDV -1a, -1b, -1d, -1f, -1h and -1l). The serum samples that gave the peak antibody titer to the homologous strains were used to perform cross neutralization assays. The highest homologous antibody titer (1:5160) was obtained against BVDV-1h. Regarding the cross neutralizing (heterologous) antibodies, the lowest titer (1:20) was produced by the BVDV-1f antiserum against the BVDV-1a and BVDV1-b viruses. The highest cross neutralizing titer (1:2580) achieved by the BVDV-1h antiserum was against the BVDV-1b strain. The cross neutralization results indicated particular serological differences between the recently described subgroup (BVDV-1l) and BVDV -1a/-1b, which are widely used in commercial vaccines. Considering the cross neutralization titers, it is concluded that selected BVDV-1l and BVDV-1h strains can be used for the development of diagnostic and control tools.


      PubDate: 2014-11-21T16:05:20Z
       
  • Proteomic analysis of Lawsonia intracellularis reveals expression of outer
           membrane proteins during infection
    • Abstract: Publication date: Available online 8 November 2014
      Source:Veterinary Microbiology
      Author(s): Eleanor Watson , M. Pilar Alberdi , Neil F. Inglis , Alex Lainson , Megan E. Porter , Erin Manson , Lisa Imrie , Kevin Mclean , David G.E. Smith
      Lawsonia intracellularis is the aetiological agent of the commercially significant porcine disease, proliferative enteropathy. Current understanding of host–pathogen interaction is limited due to the fastidious microaerophilic obligate intracellular nature of the bacterium. In the present study, expression of bacterial proteins during infection was investigated using a mass spectrometry approach. LC-ESI-MS/MS analysis of two isolates of L. intracellularis from heavily-infected epithelial cell cultures and database mining using fully annotated L. intracellularis genome sequences identified 19 proteins. According to the Clusters of Orthologous Groups (COG) functional classification, proteins were identified with roles in cell metabolism, protein synthesis and oxidative stress protection; seven proteins with putative or unknown function were also identified. Detailed bioinformatic analyses of five uncharacterised proteins, which were expressed by both isolates, identified domains and motifs common to other outer membrane-associated proteins with important roles in pathogenesis including adherence and invasion. Analysis of recombinant proteins on Western blots using immune sera from L. intracellularis-infected pigs identified two proteins, LI0841 and LI0902 as antigenic. The detection of five outer membrane proteins expressed during infection, including two antigenic proteins, demonstrates the potential of this approach to interrogate L. intracellularis host–pathogen interactions and identify novel targets which may be exploited in disease control.


      PubDate: 2014-11-21T16:05:20Z
       
  • Pseudomonas fluorescens: Fur is required for multiple biological
           properties associated with pathogenesis
    • Abstract: Publication date: Available online 11 November 2014
      Source:Veterinary Microbiology
      Author(s): Ze-jun Zhou , Lu Zhang , Li Sun
      Pseudomonas fluorescens, a Gram-negative bacterium, is an aquaculture pathogen with a broad host range. In a previous study, we had demonstrated that knockout of the fur gene of a pathogenic P. fluorescens strain, TSS, resulted in profound virulence attenuation. In this work, we studied the properties of the fur knockout mutant, TFM, in comparison with the wild type strain TSS. We found that compared to TSS, TFM (i) was impaired in siderophore production and extracellular enzyme activities, (ii) exhibited altered global polarity, (iii) was dramatically reduced in the ability to resist oxidative stress, (iv) showed higher tolerance to manganese, and (v) exhibited significantly reduced cytotoxicity. When incubated with cultured host cells, TFM displayed a cellular binding index much lower than that of TSS. Neither TFM nor TSS was able to survive and replicate in host cells. Following inoculation into Japanese flounder (Paralichthys olivaceus), TSS upregulated the expression of a wide range of genes involved in innate immunity, notably IL-1β and two CC chemokines. In contrast, TFM caused significant inductions of only a few genes and to much lower magnitudes than TSS. Given the strong inductions of IL-1β and the two chemokines by TSS, the effect of these three genes on P. fluorescens invasion was examined. The results showed that overexpression of these genes in flounder significantly inhibited TSS dissemination into and colonization of host tissues. Taken together, these results indicate that Fur is required for multiple processes associated with virulence, and that proinflammatory cytokines and chemokines likely play important roles in the clearance of P. fluorescens infection.


      PubDate: 2014-11-21T16:05:20Z
       
  • Multiple sampling and discriminatory fingerprinting reveals clonally
           complex and compartmentalized infections by M bovis in cattle
    • Abstract: Publication date: Available online 13 November 2014
      Source:Veterinary Microbiology
      Author(s): Yurena Navarro , Beatriz Romero , María Francisca Copano , Emilio Bouza , Lucas Domínguez , Lucía de Juan , Darío García-de-Viedma
      The combination of new genotyping tools and a more exhaustive sampling policy in the analysis of infection by Mycobacterium tuberculosis has shown that infection by this pathogen is more complex than initially expected. Mixed infections, coexistence of clonal variants from a parental strain, and compartmentalized infections are all different modalities of this clonal complexity. Until recently, genotyping of Mycobacterium bovis in animal populations was based on spoligotyping and analysis of a single isolate per infection; therefore, clonal complexity is probably underdetected. We used multiple sampling combined with highly discriminatory MIRU-VNTR to study compartmentalized infections by M. bovis in a low-tuberculosis prevalence setting. We spoligotyped the M. bovis isolates from two or more anatomic locations sampled from 55 animals on 39 independent farms. Compartmentalized infections, with two different strains infecting independent lymph nodes in the same animal, were found in six cases (10.9%). MIRU-VNTR analysis confirmed that the compartmentalization was strict and that only one strain was present in each infected node. MIRU-VNTR analysis of additional infected animals on one of the farms confirmed that the compartmentalized infection was a consequence of superinfection, since the two strains were independently infecting other animals. This same analysis revealed the emergence of a microevolved clonal variant in one of the lymph nodes of the compartmentalized animal. Clonal complexity must also be taken into consideration in M. bovis infection, even in low-prevalence settings, and analyses must be adapted to detect it and increase the accuracy of molecular epidemiology studies.


      PubDate: 2014-11-21T16:05:20Z
       
  • Multilocus Sequence Typing of Mycoplasma bovis Reveals Host-Specific
           Genotypes in Cattle versus Bison
    • Abstract: Publication date: Available online 11 November 2014
      Source:Veterinary Microbiology
      Author(s): Karen B. Register , Luke Thole , Ricardo F. Rosenbush , F. Chris Minion
      Mycoplasma bovis is a primary agent of mastitis, pneumonia and arthritis in cattle and the bacterium most frequently isolated from the polymicrobial syndrome known as bovine respiratory disease complex. Recently, M. bovis has emerged as a significant health problem in bison, causing necrotic pharyngitis, pneumonia, dystocia and abortion. Whether isolates from cattle and bison comprise genetically distinct populations is unknown. This study describes the development of a highly discriminatory multilocus sequencing typing (MLST) method for M. bovis and its use to investigate the population structure of the bacterium. Genome sequences from six M. bovis isolates were used for selection of gene targets. Seven of 44 housekeeping genes initially evaluated were selected as targets on the basis of sequence variability and distribution within the genome. For each gene target sequence, four to seven alleles could be distinguished that collectively define 32 sequence types (STs) from a collection of 94 cattle isolates and 42 bison isolates. A phylogeny based on concatenated target gene sequences of each isolate revealed that bison isolates are genetically distinct from strains that infect cattle, suggesting recent disease outbreaks in bison may be due to the emergence of unique genetic variants. No correlation was found between ST and disease presentation or geographic origin. MLST data reported here were used to populate a newly created and publicly available, curated database to which researchers can contribute. The MLST scheme and database provide novel tools for exploring the population structure of M. bovis and tracking the evolution and spread of strains.


      PubDate: 2014-11-21T16:05:20Z
       
  • Evidence for the vertical transmission of Sunshine virus
    • Abstract: Publication date: Available online 18 November 2014
      Source:Veterinary Microbiology
      Author(s): Timothy H. Hyndman , Robert S.P. Johnson
      Sunshine virus is a paramyxovirus of pythons associated with neurorespiratory disease and mortalities. This report provides evidence for its vertical transmission. In a collection of over 200 Australian pythons, a dam and a sire, both carpet pythons (Morelia spilota), were PCR-positive for Sunshine virus at a time when the dam was likely to have been gravid. A clutch of 21 eggs was laid and three non-viable eggs were tested for the presence of Sunshine virus by PCR. One egg had been incubating for 34 days while the other two had been incubating for 49 days. The surface of all three eggs was negative for Sunshine virus but swabs of the allantois and amnion were positive in all three eggs. Embryo tissue samples were tested from the two 49 day old eggs. From one embryo, a sample of brain and a pooled sample of lung, liver, kidney and intestine were positive, while for the other embryo, a pooled sample of lung, liver, kidney, intestine and brain was positive. Fourteen of the 21 eggs hatched and all hatchlings were tested by PCR at least once between the ages of 53 and 229 days old. All hatchlings were PCR-negative for Sunshine virus.


      PubDate: 2014-11-21T16:05:20Z
       
  • Diversity of Shiga toxin-producing Escherichia coli in sheep flocks of
           Paraná State, southern Brazil
    • Abstract: Publication date: Available online 13 November 2014
      Source:Veterinary Microbiology
      Author(s): Fernando Henrique Martins , Beatriz Ernestina Cabilio Guth , Roxane Maria Piazza , Sylvia Cardoso Leão , Agostinho Ludovico , Marilúcia Santos Ludovico , Ghizlane Dahbi , Juan Marzoa , Azucena Mora , Jorge Blanco , Jacinta Sanchez Pelayo
      Sheep constitute an important source of zoonotic pathogens as Shiga toxin-producing Escherichia coli (STEC). In this study, the prevalence, serotypes and virulence profiles of STEC were investigated among 130 healthy sheep from small and medium farms in southern Brazil. STEC was isolated from 65 (50%) of the tested animals and detected in all flocks. A total of 70 STEC isolates were characterized, and belonged to 23 different O:H serotypes, many of which associated with human disease, including hemolytic-uremic syndrome (HUS). Among the serotypes identified, O76:H19 and O65:H- were the most common, and O75:H14 and O169:H7 have not been previously reported in STEC strains. Most of STEC isolates harbored only stx1, whereas the Stx2b subtype was the most common among those carrying stx2. Enterohemolysin (ehxA) and intimin (eae) genes were detected in 61 (87.1%) and four (5.7%) isolates, respectively. Genes encoding putative adhesins (saa, iha, lpf O113 ) and toxins (subAB and cdtV) were also observed. The majority of the isolates displayed virulence features related to pathogenesis of STEC, such as adherence to epithelial cells, high cytotoxicity and enterohemolytic activity. Ovine STEC isolates belonged mostly to phylogenetic group B1. PFGE revealed particular clones distributed in some farms, as well as variations in the degree of genetic similarity within serotypes examined. In conclusion, STEC are widely distributed in southern Brazilian sheep, and belonged mainly to serotypes that are not commonly reported in other regions, such as O76:H19 and O65:H-. A geographical variation in the distribution of STEC serotypes seems to occur in sheep.


      PubDate: 2014-11-21T16:05:20Z
       
  • Divergence of a strain of Pseudomonas aeruginosa during an outbreak of
           ovine mastitis in Sardinia
    • Abstract: Publication date: Available online 20 November 2014
      Source:Veterinary Microbiology
      Author(s): Elli A. Wright , Valeria Di Lorenzo , Claudia Trappetti , Manuele Liciardi , Germano Orru , Carlo Viti , Christina Bronowski , Amanda J. Hall , Alistair C. Darby , Marco Oggioni , Craig Winstanley
      Bacterial infections causing mastitis in sheep can result in severe economic losses for farmers. A large survey of milk samples from ewes with mastitis in Sardinia, Italy, indicated an increasing prevalence of Pseudomonas aeruginosa infections. It has been shown previously that during chronic, biofilm-associated infections P. aeruginosa populations diversify. We report the phenotypic and genomic characterisation of two clonal P. aeruginosa isolates (PSE305 and PSE306) from a mastitis infection outbreak, representing distinct colony morphology variants. In addition to pigment production, PSE305 and PSE306 differed in phenotypic characteristics including biofilm formation, utilisation of various carbon and nitrogen sources, twitching motility. We found higher levels of expression of genes associated with biofilm formation (pelB) and twitching motility (flgD) in PSE305, compared to the biofilm and twitching-defective PSE306. Comparative genomics analysis revealed single nucleotide polymorphisms (SNPs) and minor insertion/deletion variations between PSE305 and PSE306, including a SNP mutation in the pilP gene of PSE306. By introducing a wild-type pilP gene we were able to partially complement the defective twitching motility of PSE306. There were also three larger regions of difference between the two genomes, indicating genomic instability. Hence, we have demonstrated that P. aeruginosa population divergence can occur during an outbreak of mastitis, leading to significant variations in phenotype and genotype, and resembling the behaviour of P. aeruginosa during chronic biofilm-associated infections.


      PubDate: 2014-11-21T16:05:20Z
       
  • Effects of different NS genes of avian influenza viruses and amino acid
           changes on pathogenicity of recombinant A/Puerto Rico/8/34 viruses
    • Abstract: Publication date: Available online 18 November 2014
      Source:Veterinary Microbiology
      Author(s): Il-Hwan Kim , Hyuk-Joon Kwon , Su-Hyung Lee , Dae-Yong Kim , Jae-Hong Kim
      To examine the effects of the NS1 and NEP genes of avian influenza viruses (AIVs) on pathogenicity in mice, we generated recombinant PR8 viruses containing 3 different NS genes of AIVs. In contrast to the reverse genetics-generated PR8 (rPR8) strain and other recombinant viruses, the recombinant virus rPR8-NS(0028), which contained the NS gene of A/chicken/KBNP-0028/2000 (H9N2) (0028), was non-pathogenic to mice. The novel single mutations of 0028 NS1 to corresponding amino acid of PR8 NS1, G139D and S151T increased the pathogenicity of rPR8-NS(0028). The replacement of the PL motifs (EPEV or RSEV) of pathogenic recombinant viruses with that of 0028 (GSEV) did not reduce the pathogenicity of the viruses. However, a recombinant virus with an EPEV-grafted 0028 NS gene was more pathogenic than rPR8-NS(0028) but less than rPR8. The lower pathogenicity of rPR8-NS(0028) might be associated with the lower virus titer and IFN-β level in the lungs of infected mice, and be attributed to G139, S151 and GSEV-PL motif of NS1 gene of 0028. In conclusion we defined new amino acid residues of NS1 related to mice pathogenicity and the presence of pathogenic NS genes among low pathogenic AIVs may encourage continuous monitoring of their mammalian pathogenicity.
      Graphical abstract image

      PubDate: 2014-11-21T16:05:20Z
       
  • Characterization of Mannheimia haemolytica biofilm formation in vitro
    • Abstract: Publication date: Available online 20 November 2014
      Source:Veterinary Microbiology
      Author(s): Ismail Boukahil , Charles J. Czuprynski
      Mannheimia haemolytica is the primary bacterial agent in the bovine respiratory disease complex. It is thought that M. haemolytica colonizes the tonsillar crypts of cattle as a commensal and subsequently descends into the lungs to cause disease. Many bacterial species persist in the host as biofilms. There is limited information about the ability of M. haemolytica to form biofilms. The aim of this study was to develop an in vitro model for M. haemolytica biofilm formation. We found that M. haemolytica required at least 36hours to form robust biofilms on plastic in vitro when incubated in RPMI-1640 tissue culture medium at 37°C, with maximal biofilm formation being evident at 48hours. Biofilm formation was inhibited by adding the monosaccharides D (+) galactose and D (+) mannose to the growth medium. Addition of antibodies to the M. haemolytica surface protein OmpA also reduced biofilm formation. Upon evaluating the macromolecules within the biofilm extracellular polymeric substance we found it contained 9.7μg/cm2 of protein, 0.81μg/cm2 of total carbohydrate, and 0.47μg/cm2 of extracellular DNA. Furthermore, proteinase K treatment significantly decreased biofilms (P<0. 05) while α-amylase and micrococcal nuclease decreased biofilms to a lesser extent. M. haemolytica biofilm cells were more resistant than planktonic cells to the antibiotics florfenicol, gentamicin, and tulathromycin. These results provide evidence that M. haemolytica can form biofilms, which could contribute to its ability to persist as a commensal in the bovine upper respiratory tract.


      PubDate: 2014-11-21T16:05:20Z
       
  • Identification and molecular characterization of novel and divergent
           HoBi-like pestiviruses from naturally infected cattle in India
    • Abstract: Publication date: Available online 30 September 2014
      Source:Veterinary Microbiology
      Author(s): N. Mishra , K. Rajukumar , A. Pateriya , M. Kumar , P. Dubey , S.P. Behera , A. Verma , P. Bhardwaj , D.D. Kulkarni , D. Vijaykrishna , N.D. Reddy
      HoBi-like pestiviruses have been sporadically reported from naturally infected cattle in South America, Asia and Europe. While the closely related bovine viral diarrhea virus 1 (BVDV-1) and BVDV-2 have been reported from cattle in India, the prevalence and diversity of HoBi-like viruses have not yet been studied. Here we report the genetic diversity and molecular characteristics of HoBi-like viruses, through systematic surveillance in cattle (n=1049) from 21 dairy farms across India during 2012--2013. On the basis of real-time RT-PCR, virus isolation and nucleotide sequencing results, of the 20 pestivirus positive cattle, HoBi-like viruses were identified in 19 cattle from four farms in three states and BVDV-1b in one cattle. Phylogenetic analysis of 5′-UTR and Npro region identified the circulation of two lineages of HoBi-like viruses in India, that were distinct to those circulating globally, highlighting the independent evolution of at least three lineages of HoBi-like viruses globally. Antigenic differences were also evident between the two Indian lineages. In addition to revealing that HoBi-like virus may be more widespread in Indian cattle than previously reported, this study shows greater genetic divergence of HoBi-like viruses indicating a need for continued pestivirus surveillance in cattle.


      PubDate: 2014-09-30T18:41:59Z
       
  • Pathogenesis in lambs and sequence analysis of putative virulence genes of
           Brazilian orf virus isolates
    • Abstract: Publication date: Available online 28 September 2014
      Source:Veterinary Microbiology
      Author(s): Mathias Martins , Juliana F. Cargnelutti , Rudi Weiblen , Eduardo F. Flores
      The parapoxvirus orf virus (ORFV) is the agent of contagious ecthyma, an ubiquitous mucocutaneous disease of sheep and goats that may present variable clinical presentations. We herein studied the pathogenesis of ORFV infection in lambs and analyzed three putative virulence genes of four Brazilian ORFV isolates. Lambs inoculated in the labial commissures with each ORFV isolate (n=4, viral titer 105.6 TCID50/ml) developed classical orf lesions, characterized by a progressive course of erythema/macules, vesicles, pustules and proliferative scabs. Lesions lasted an average of 22.9 days (18–26) and virus shedding was detected for approximately 24.6 days (18–30). Two isolates (SV269/11 and SV820/10) produced more severe, long-lasting lesions resulting in highest clinical scores. Lambs inoculated with isolate SV581/11 developed lesions markedly milder (lower clinical scores [p<0.05]) and more limited than the other groups. Virus shedding by SV581/11 group, however, lasted similarly or even longer than the other groups. Sequence analysis of three virulence genes (VEGF, VIR and IL-10v) revealed amino acid deletions and mutations in VEGF and IL-10v genes of SV581/11 and SV252/11, the isolate(s) producing milder lesions. Additionally, the VEGF gene of isolate SV581/11 presented the lowest amino acid identity with the other isolates and with ORFV standard strain OV-IA82. Thus, these results demonstrate that ORFV isolates may display differential virulence in lambs and these differences might be associated with genetic changes in putative virulence genes.


      PubDate: 2014-09-30T18:41:59Z
       
  • Pathogenicity study in sheep using reverse-genetics-based reassortant
           bluetongue viruses
    • Abstract: Publication date: Available online 30 September 2014
      Source:Veterinary Microbiology
      Author(s): Cristina C. Celma , Bishnupriya Bhattacharya , Michael Eschbaumer , Kerstin Wernike , Martin Beer , Polly Roy
      Bluetongue (BT) disease, caused by the non-enveloped Bluetongue virus (BTV) belonging to the Reoviridae family, is an economically important disease that affects a wide range of wild and domestic ruminants. Currently, 26 different serotypes of BTV are recognized in the world, of which BTV-8 has been found to exhibit one of the most virulent manifestations of BT disease in livestock. In recent years incursions of BTV-8 in Europe have resulted in significant morbidity and mortality not only in sheep but also in cattle. The molecular and genetic basis of BTV-8 pathogenesis is not known. To understand the genetic basis of BTV-8 pathogenicity we generated reassortant viruses by replacing the 3 most variable genes, S2, S6 and S10 of a recent isolate of BTV-8, in different combinations into the backbone of an attenuated strain of BTV-1. The growth profiles of these reassortant viruses were then analyzed in two different ovine cell lines derived from different organs, kidney and thymus. Distinct patterns for each reassortant virus in these two cell lines were observed. To determine the pathogenicity of these reassortant viruses, groups of BTV-susceptible sheep were infected with each of these viruses. The data suggested that the clinical manifestations of these two different serotypes, BTV-1 and BTV-8, were slightly distinct and BTV-1, when comprising all 3 genome segments of BTV-8, behaved differently to BTV-1. Our results also suggested that the molecular basis of BT disease is highly complex.


      PubDate: 2014-09-30T18:41:59Z
       
 
 
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